Project period: 2 3 25-2 2 27PROJECT title: mapping local soil moisture with unmanned aerial vehicle based l-band sensorsoil moisture is an important variable in the terrestrial hydrological cycle

The U.S. Geological Survey (USGS) awarded a $319,547 cooperative agreement under the USGS Research and Data Collection program (CFDA 15.808) to the Rector & Visitors of the University of Virginia (UVA) to map local soil moisture at high spatial resolution (5m) using an unmanned aerial vehicle (UAV) mounted L-band passive radiometer. The project aims to overcome limitations of ground-based monitoring and modeling systems by collecting soil moisture data at soil moisture testbeds developed by the Next Generation Water Observing Systems (NGWOS) program. The award supports collaboration on related journal articles and student advisory panels, with the data expected to benefit applications such as floods, droughts, landslides, and wildfires. The project period is from Feb 3, 2025 to Feb 2, 2030.

Observations ormodeling of soil moisture at high spatial resolution has proven difficult due to complexinteractions between the land surface and atmosphere that make soil moisture highly variable intime and space. In terms of in-situ observations, maintaining a high spatial density is timeconsuming and expensive. Satellite observations are limited by a tradeoff between spatialresolution and temporal revisits, and high spatial observations can only be achieved if thetemporal repeat is infrequent. In terms of modeling, high spatial resolution of soil moisture islimited by the uncertainty related to inputs such as precipitation, soil and vegetation information, topography and other meteorological observations along with the inherent limitations of earthsystem models. In this project, propose to use an uncrewed aerial vehicle (UAV) mounted lbandpassive radiometer to achieve high spatial resolution ( 5M) soil moisture observations toovercome the limitation of ground-based monitoring and modeling systems. Propose to flyrepeat surveys at soil moisture testbeds developed by the next generation water observingsystems (ngwos) program and to train and develop USGS scientists in the use of such data.anticipate collaborations on related journal articles and student advisory panels. Suchinformation would be useful for numerous applications such as floods, droughts, landslides andwildfires.